Health: How Dengue Spreads

The common response to an outbreak of dengue fever, spread by the bite of the Aedes aegypti mosquito, is to spray pesticide in public places like schools and markets. But a new study indicates the focus should be on people's neighborhoods and homes instead.

Cases of the tropical disease that causes debilitating pain have been rising, and more than half the world's population is considered at risk. There is no vaccine for dengue, so the only way to control outbreaks is to kill the mosquitoes that spread it.

Scientists from several universities tracked the virus through two neighborhoods in the crowded city of Iquitos, in the Peruvian rain forest. They mapped where dengue patients lived and who they visited before the onset of fever. They collected mosquitoes from those locations and tested them for the virus. Two-thirds of the patients had visited the same houses.

Emory University disease ecologist Gonzalo Vazques-Prokopec reports "people appear to be getting infected most often in homes, but not necessarily their own homes." The findings suggest a different approach to surveillance and control of dengue fever.

The report is published in the Proceedings of the National Academy of Sciences.